Methods and compositions for intravaginal contraception

ABSTRACT

A pressurized contraception composition in an aerosol container and adapted to form a spray upon release of pressure therefrom which composition is a liquid inside the container and forms a gel on contact with living tissue and process employing same, whereby the composition comprises water, propellant, a polyoxyethylene-polyoxypropylene copolymer, and preferably a sperm function inhibitor.

BACKGROUND OF THE INVENTION

After two decades of effort to devise satisfactory contraceptive methodswhich depend on metabolic control mechanisms (oral contraceptives andprogestational inserts) or on intra-uterine mechanical disruption, i.e.intrauterine devices (IUD's); alternative methods which depend onbarriers (diaphragms, condoms) and on topical application of spermicidesor other contraceptives (intravaginal foams or suppositories) have notbecome obsolete, and are still in wide use. These methods attractconsiderable interest due to their safety, freedom from undesirable sideeffects, and relative accessibility, without the need for a physician'sintervention. The present invention relates to compositions for, andmethods of, contraception based on topical intravaginal application ofspermicides or other antifertility agents which inhibit sperm function.

Present formulations for intravaginal application of sperm functioninhibitors are designed to insure coverage of the entire vaginal vaultwith the active ingredient (usually a surfactant, and typicallynonoxynol-9, a nonionic surfactant).

One method for intravaginal application comprises supplying thecontraceptive composition in the form of a gel.

The preparation of aqueous gels employing as gelling agentspolyoxyethylene-polyoxypropylene block copolymers is well known to thoseskilled in the art and is taught in several patents including U.S. Pat.Nos. 3,740,421, 3,748,276, and 3,749,465.

U.S. Pat. No. 4,368,186 discloses that compositions designed forintravaginal application containing polyoxyethylene-polyoxypropyleneblock copolymers in substantial amount, have unexpected inherentspermicidal properties.

While the form of application of the spermicide may be varied, such as,gel, foam, cream, or a suppository designed to disintegrate and spreadby means of, for example, an effervescent dissolution process, all ofthese application methods are basically similar to barrier methods inthat they depend in the final analysis, on the spermicide encounteringand destroying all sperm which enter the vagina.

For this reason, the present formulations and method of applicationcannot be considered totally satisfactory solutions to the problem. Ifthey succeed in coverage of the entire vaginal surface, they areinherently messy and unaesthetic. If they fail to do so, they arerelatively ineffective; a particular problem with those formulationsdesigned in the form of dissolving suppositories.

It is known in the prior art to apply gels from aerosol containers ascan be seen by the following:

U.S. Pat. No. 3,751,562, issued Aug. 7, 1973, to Nichols, discloses anaerosol gel formulation employing an oxyethylated fatty alcohol, mineraloil, iodine and water.

U.S. Pat. No. 4,293,542, issued Oct. 6, 1981, to Lang et al, disclosesaerosol formulations which can be an aqueous gel containing oxyethylatedfatty alcohols and a gel-forming agent and, as an essential component, apyridine derivative. Another aerosol gel composition is disclosed inU.S. Pat. No. 4,001,391.

While it is known in the art to apply gel compositions by the use ofaerosol-type containers, filling an aerosol container with a gelpresents problems.

British No. 1,444,334 discloses an aerosol gel composition which may beemployed as a shaving cream and which contains as a gelling agent apolyoxyethylene-polyoxypropylene block copolymer. An essential componentof the composition is a water-soluble soap. This patent is concernedwith the problem of expelling a gel from an aerosol container andparticularly avoiding cavitation around the dip tube. Accordingly, thecompressed gas or liquified gaseous propellant is required to besubstantially insoluble in the gel so that it can act in the manner of apiston to force the gel from the container without cavitation. Aerosolgel compositions are also described in U.S. patent application Ser. Nos.513,439; 524,985; 525,147 and 525,148.

SUMMARY OF THE INVENTION

The instant invention relates to a greatly improved method ofintravaginal application of a spermicide characterized by greatlyimproved coverage over prior art methods and a composition employed insuch method, whereby the composition is in the form of a gel appliedfrom an aerosol container. As pointed out above and particularly evidentfrom British Pat. No. 1,444,334, there are filling and cavitationproblems inherent in the use of gels in aerosol containers. Theseproblems are overcome in accordance with the instant invention by theuse of a pressurized composition which may be sprayed from an aerosolcontainer and which is liquid inside the container and forms a gel oncontact with living tissue. This is accomplished preferably by thecombination of water, propellant, volatile solvent and certainpolyoxyethylene-polyoxypropylene block copolymers. As employedthroughout the instant specification and claims, the term "solvent"means a solvent for the gel composition of this invention. While thecomposition itself acts as a sperm function inhibitor, the compositionpreferably contains a conventional sperm function inhibitor. It may alsocontain at least one non toxic adjuvant such as other pharmaceuticals,emollients, etc. which are pharmaceutically acceptable and which do notirritate the mucous membrane.

The polyoxyethylene-polyoxypropylene block copolymer has apolyoxypropylene hydrophobe molecular weight of about 3000 to 4500 andthe oxyethylene groups constitute 50 to 90 percent preferably 60 to 80percent of the total weight of the copolymer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The aerosol composition of the instant invention should be liquid atambient temperature, i.e. from about 20 °to about 30° C., but uponwarming, to about 35° C. or higher should become a viscous gel or afoamy paste-like solid. This may be accomplished by varying the ratio ofsurfactant and water as well as the amount and type of propellant used.This may also be accomplished by the use of a volatile solvent in thecomposition, particularly where the propellant is not soluble in thecomposition or vice versa.

The aerosol composition of the instant invention comprises by weightabout 20 to 60 percent water, about 20 to 80 percent propellant, about7.5 to 30 percent of the polyoxyethylene-polyoxypropylene blockcopolymer, 0 to about 1.5 percent, preferably about 0.02 to 1.0 percent,of a sperm function inhibitor, about 5 to about 40 percent, preferablyabout 10 to 25 percent, of a non-propellant volatile solvent, and 0 toabout 30 percent, preferably about 5 to 10 percent adjuvants. By the useof a propellant which is also a solvent, the need for a non-propellantsolvent is eliminated and thus the amount can be 0. Also the need forany solvent may be eliminated by proper selection of the copolymer andits concentration.

The polyoxypropylene-polyoxyethylene block copolymer of use in theinvention is a cogeneric mixture of conjugated polyoxypropylenepolyoxyethylene compounds having as a hydrophobe, a polyoxypropylenepolymer having a molecular weight of about 3000 to 4500. Thepolyoxypropylene compounds are prepared by first condensing propyleneoxide with an organic compound containing a plurality of reactivehydrogen atoms to prepare a polyoxypropylene polymer having a molecularweight of about 3000 to 4500 and subsequently condensing ethylene oxidetherewith. The compounds used in this invention conform to the followinggeneral formula:

    Y[(C.sub.3 H.sub.6 O).sub.n --E--H].sub.x                  (A)

wherein Y is the residue of a water soluble organic compound containingtherein x active hydrogen atoms; n is an integer; x is an integergreater than 1; the values of n and x are such that the molecular weightof the compound, exclusive of E, is about 3000 to 4500 as determined byhydroxyl number; E is a polyoxyalkylene chain wherein the oxygen/carbonatom ratio is at least 0.5, and E constitutes 50 to 90 percent of thetotal weight of the compound.

The polyoxypropylene polymer, which is an intermediate in thepreparation of the compounds of use in this invention, has the followingstructure:

    Y[(C.sub.3 H.sub.6 O).sub.n H].sub.x                       (B)

wherein Y, n and x are defined as in Formula A above.

The preferred compounds of use in this invention are prepared bycondensing ethylene oxide in an amount between 50 and 90 percent of thetotal weight of the resultant compound, with the polyoxypropylenepolymer. These compounds have the following formula:

    Y[(C.sub.3 H.sub.6 O).sub.n (C.sub.2 H.sub.4 O).sub.m H].sub.x (C)

wherein Y, n and x are defined as in Formula A and m has a value suchthat the oxyethylene groups constitute about 50 to 90 percent of thetotal weight of the compound.

The hydrophilic portion of the polyoxyalkylene compounds may be suppliedin whole or in part by other polyoxyalkylene chains in lieu of thepolyoxyethylene chain set forth in Formula C. Any polyoxyalkylene chainmay be used provided that the oxygen/carbon atom ratio is at least 0.5.

Examples of a water-soluble organic compound containing therein x activehydrogen atoms, the residue of which is Y, are the initiators which mayinclude water, diols such as propane diol, butanediol, triols such asglycerol and trimethylol propane, tetrols such as pentaerythritol aswell as initiators containing more than four hydroxyl groups such ashexitol or sucrose. Also, amines and other low molecular weightwater-soluble compounds having two or more active hydrogen atoms, suchas ethylene diamine or diethylene triamine, may be used as theinitiator. Preferably used is propylene glycol. More preferably used is1,2-propylene glycol.

The propylene oxide used in making the hydrophobic polyoxypropylenepolymer, which is an intermediate in the preparation of the compoundsused in this invention, may be replaced with up to 30 percent by weightof butylene oxide or ethylene oxide when added as a mixture with thepropylene oxide. Also, up to 30 percent by weight of propylene oxide orbutylene oxide may be used to replace ethylene oxide, when added as amixture with ethylene oxide, in preparing the surfactants used in thisinvention.

When ethylene oxide is condensed with a polyoxypropylene glycol of about3000 to 4500 molecular weight and derived from a propanediol initiator,the resulting compounds have the following structure:

    HO(C.sub.2 H.sub.4 O).sub.m (C.sub.3 H.sub.6 O).sub.n (C.sub.2 H.sub.4 O).sub.m H                                                (D)

wherein n is defined as set forth with respect to formula A and m has avalue such that the oxyethylene groups constitute about 50 to 90 percentof the total weight of the compound.

Surfactants of the invention, conforming to structures C and D above,are those surfactants which have a hydrophobe molecular weight ofbetween about 3000 and 4500 and ethylene oxide groups in amount of fromabout 50 to 90 percent of the total weight of the surfactant.

A composition which is a liquid inside the container and forms a gel oncontact with living tissue which does not include a volatile solvent inthe composition may be obtained by the use of a combination of water,non solvent propellant and polyoxyethylene-polyoxypropylene blockcopolymer. More specifically, by the proper selection of thewater/copolymer ratio the composition would be a liquid at ambienttemperature (20° C. to 25° C.) and would form a gel on being exposed tobody heat at atmospheric pressure. Such composition would have a maximumwater-to-copolymer ratio of 5.7:1.

Where the water to copolymer ratio is less than 5.7:1 a volatile solventis incorporated in the composition which evaporates upon contact withbody heat whereby the liquid becomes a gel. The use of the solventextends the water:copolymer ratio whereby it can be less than 5.7:1.Suitable solvents include alcohols such as methyl, ethyl and propyl,ketones such as dimethyl and ethyl methyl, ethers such as methyl, ethyl,methyl-ethyl, and similar ethers, and chlorinated alkanes such asdichloromethane. A non-volatile solvent such as liquid polyethyleneglycols, propylene glycol, glycerol, dipropylene glycol, etc., can beused together with a volatile solvent, provided the mixture ishomogeneous.

The propellants can be any one or a blend of the following as examples:propane, isobutane and other petroleum distillates, nitrogen, carbondioxide, dimethylether, ethylmethylether, methylene chloride, vinylchloride and fluorochlorohydrocarbons. The latter include Freon 115,pentafluorochloroethane and Freon C-318, octafluorocyclobutane. Wherethe composition is soluble in the propellant, or where the propellant issoluble in the composition, a non-propellant volatile solvent may not beneeded. Such volatile solvent propellants include dimethylether,methylethylether and methylene chloride.

The product may form a foamy gel after expelling from the aerosolcontainer which is firm or rigid and which will form upon body contact.For this purpose, small amounts of conventional foaming agents wellknown to those skilled in the art such as nonionic, amphoteric, andanionic surfactants may be employed. Such foaming agents includehigh-foaming ethylene oxide adducts such as fatty alcohol ethoxylatesand potassium lauryl sulfates and lauryl ether sulfates. Other examplesof such agents are triethanolamine lauryl sulfate, sodium dodecylbenzenesulfonate, water-soluble polyoxyethylene ethers of alkyl-substitutedphenols, amine oxides and phosphate ester based surfactants.

In the context of the present invention, "sperm function inhibitor"refers to compounds which render sperm incapable of fertilizing thefemale subject, whether by immobilizing, altering, or killing the sperm.These agents are in the general contraceptive class, but aredistinguished by directing their effects to the capacity of the sperm tofertilize, rather than altering the metabolism of the female, as is thecase with, for example, progestational contraceptives. Examples of suchsperm function inhibitors include surfactants such as the widely usednonoxynol-9 or 10, or octoxynol-9 or 10, which appear to be spermicidal;certain mercuric salts, which also kill sperm, certain 1-substitutedimidazoles which are both spermicidal and spermatostatic--i.e.,immobilizing; and peptide or other synthetic inhibitors of the spermproteases which mediate the fertilization of the ovum. Other spermfunction inhibitors include benzalkonium blends and 1-substitutedimidazole sulfates. Nonoxynol-9 is a well known spermicide having thechemical name p-nonylphenoxypolyethoxyethanol. Combinations of two ormore of the above may also be included.

The spermicidal properties of the water polyoxyalkylene polyol gel aloneare clearly advantageous in enhancing the effect of any additional spermfunction inhibitor used as an active ingredient. Said gels have beenshown to immobilize sperm in vitro and to reduce fertilization in vivo.

The ability of the composition to deliver the active ingredientrepresents a more sophisticated approach to the problem of intravaginalcontraception than has previously been disclosed. Clearly it isnecessary, to achieve the goal of contraception, to affect only thosesperm which actually enter the uterus. Therefore, if the sperm functioninhibitor can be concentrated in the area of the cervix, the pathwaythrough which the sperm must enter and if large amounts of agent aresoluble therein, the purpose of the method can be achieved, without anexcess of material being required.

By the use of an aerosol container containing the composition of thisinvention which is a liquid inside the container and forms a gel oncontact with living tissue, it is easier to achieve proper placement ofthe gel near the cervix. This is particularly true if the aerosolcontainer outlet is provided with a small tube several inches in length,making it possible to apply the gel directly to the area of the cervixwhere the gel is needed. Such tubes are common in the aerosol artparticularly exemplified by aerosol containers employed for applyingcarburetor cleaners to the inside of an automotive carburetor.

Many and various adjuvants are generally also included. The amount ofsuch adjuvants would range from 0 to about 30 percent and where employedthe amount would be at least about 1 percent. The preferred amount isabout 5 to 10 percent by weight. By way of example, additionalpharmaceutical excipients are desirable in the composition. A suitablelower alkylene glycol, such as, for example, glycerin, may be adesirable component. This glycol or glycerol should be present in about2 percent to 30 percent by weight.

It may also be desirable to buffer the present composition so as toenhance its inherent spermicidal activity. Any suitable compatiblebuffer solution may be used, that is, weak acids and weak bases andtheir corresponding salts, to adjust to the desired pH. A useful buffersystem for the present invention is the citric acid/citrate system whichcan be adjusted to an acidic pH to enhance a spermicidal effect. Thetotal percentage of buffering components, should be in the range of 0.5percent to 2 percent of the total composition. Suitable pH ranges areapproximately 3 to 6, preferably 4.5 to 5.

Small amounts of antimicrobial preservatives such as parabens, benzylalcohol and others, and antioxidants such as BHA, BHT and others mayalso be included to preserve integrity of the preparation duringstorage. The percentage of these preservatives should be in the range of0.01 to 2 percent, preferably 0.5 to 1 percent. Other adjuvants couldinclude proteins, amino acids, electrolytes and other ingredientsnormally found in body fluids. Humectants, such as propylene glycol mayalso be included. Further adjuvants could include silicone oils. Also,other adjuvants which impart further desired qualities to the skin maybe incorporated in the compositions of the invention, e.g., lanolin orits derivatives, lecithin, higher alcohols, dipelargonate ethers oresters, coconut oil and other fatty esters, and mixtures thereof maygenerally be used in minor proportions. Furthermore, coloring materialssuch as dyes and perfumes may be used, if desired.

The method of the invention as practiced, of course, depends on theparticular circumstances of the subject, and upon the nature of theactive ingredient chosen as the sperm function inhibitor. Generally, theadministration of the composition containing the active ingredientshould take place between about eight hours to about two minutes priorto sexual intercourse. There appears to be no preferable range withinthis time frame, and therefore, the convenience of the subject is theparamount consideration. The amount of composition to be applied alsovaries with the concentration of the active ingredient and the design ofthe applicator. An effective amount is between 0.5 to 6 ml of the gelfor human subjects, with correspondingly larger or smaller amounts forother mammals. Preferably, it is desirable, from an aestheticstandpoint, for human subjects to use a minimum amount of composition,preferably 0.5 to 2 ml total volume, which is facilitated by theaccuracy of positioning of the application.

By the use of the aerosol applicator and composition of the invention,the composition can be deposited approximately at the location of thecervix, which is of course the critical surface, whereby a minimalamount of material can be employed.

The following examples are included to further illustrate the presentinvention. Unless otherwise stated, throughout the application all partsand percentages are by weight and all temperatures are in degreescentigrade.

EXAMPLE 1

A concentrate is prepared from 15 parts of apolyoxyethylene-polyoxypropylene block copolymer of the type shown informula (D) above, designated herein as copolymer #1, having apolyoxypropylene hydrophobe molecular weight of 4500 and containingoxyethylene groups in the amount of 70 percent of the total copolymerweight, 3 parts glycerine and 82 parts water. Fifty-nine parts of thisgel concentrate and 6 parts of isopropanol are placed in an aerosolcontainer. Thirty-five parts by weight of dimethylether propellant arethen added through the valve. The contents are shaken, and 1 ml sprayedonto a cervix.

A thin film forms initially after which the dimethylether andisopropanol evaporate forming a coating completely covering the cervix.This becomes a foamy gel as the solvent and propellant evaporate. Thecomposition effectively immobilizes spermatazoa.

EXAMPLE 2

A liquid composition is prepared comprising 25 parts of apolyoxyethylene-polyoxypropylene copolymer, 3 parts of methylethylether,0.1 part of nonoxynol-9, and 71.9 parts of water.

One hundred parts of the above liquid are placed in an aerosolcontainer, the container is pressurized and sealed with a valve and 50parts of a propellant, namely dimethylether, are added through thevalve. The contents are shaken and 1 ml sprayed onto the cervix. A thinfilm forms initially completely coating a cervix after which thedimethylether and ethylmethylether evaporate whereby a foamy gel formson the surface. The composition effectively immobilizes spermatazoa.

The polyoxyethylene-polyoxypropylene copolymer employed, designatedherein as copolymer #2, is a polyoxyethylene adduct of apolyoxypropylene hydrophobic base having a molecular weight of said baseof about 3200 and wherein the oxyethylene content is about 80 percent ofthe total weight of the molecule. The polyoxypropylene hydrophobic baseis prepared by reacting propylene oxide with a propanediol initiator.

EXAMPLE 3

Example 2 is repeated using 100 parts of a liquid composition comprising25.0 parts of copolymer #2, 15.0 parts of isopropyl alcohol, 1.0 partnonoxynol-9, 4.0 parts propylene glycol, and 55.0 parts water. Fiftyparts of carbon dioxide are added to the aerosol container through thevalve. When this composition is sprayed from the aerosol container ontoa cervix, a thin film forms after spraying, completely coating thecervix. This becomes a foamy gel as the solvent evaporates. Thecomposition effectively immobilizes spermatazoa.

EXAMPLE 4

Example 2 is repeated using 100 parts of a liquid composition comprising17.0 parts of copolymer designated herein as copolymer #3, 1.0 partnonoxynol-9, and 82 parts water. One hundred parts of carbon dioxide areadded to the aerosol container through the valve.

The polyoxyethylene-polyoxypropylene copolymer employed, designatedherein as copolymer #3, is a polyoxyethylene adduct of apolyoxypropylene hydrophobic base having a molecular weight of said baseof about 4000 and wherein the oxyethylene content is about 60 percent ofthe total weight of the molecule. The polyoxypropylene hydrophobic baseis prepared by reacting propylene oxide with a propanediol initiator.When this composition is sprayed from the aerosol container onto acervix, a thin film forms after spraying completely coating the cervix.This becomes a foamy gel as the solvent evaporates. The compositioneffectively immobilizes spermatazoa.

EXAMPLE 5

Example 2 is repeated using 100 parts propellant and 50 parts of theliquid composition substituting for copolymer #2 apolyoxyethylene-polyoxypropylene copolymer, designated herein ascopolymer #4, having a hydrophobe molecular weight of 3500 and whereinthe oxyethylene groups constitute about 90 percent of the totalcopolymer weight. When this composition is sprayed from the aerosolcontainer, a thin film forms after spraying on a cervix which coatscompletely. This becomes a foamy gel as the solvent evaporates. Thecomposition is effective in immobilizing spermatazoa.

EXAMPLE 6

Example 5 is repeated using 25 parts propellant and 100 parts of theliquid composition.

EXAMPLE 7

Example 2 is repeated with the exception that the liquid compositionconsists of 25.0 parts of copolymer #2, 10 parts isopropyl alcohol, 10.0parts of glycerine, 1.0 part of nonoxynol-9, 4.0 parts of acetone and 50parts of water. Fifty parts of methylene chloride propellant aresubsequently added to the aerosol container. When this composition issprayed from the aerosol container, a thin film forms after spraying ona cervix which completely coats the cervix. This becomes a foamy gel asthe solvent evaporates. The composition is effective in immobilizingspermatazoa.

EXAMPLE 8

A liquid composition is prepared comprising 15.0 parts of apolyoxyethylene-polyoxypropylene copolymer, 40 parts ofmethylethylether, 1.0 part of nonoxynol-9, and 44 parts of water.

Fifty parts of the above liquid are placed in an aerosol container, thecontainer is pressurized and sealed with a valve and 25 parts of apropellant, namely dimethylether, are added through the valve. Thecontents are shaken and 1 ml sprayed onto the cervix. A thin film formsinitially completely coating a cervix after which the dimethylether andethylmethylether evaporate whereby a foamy gel forms on the surface. Thecomposition effectively immobilizes spermatazoa.

The polyoxyethylene-polyoxypropylene copolymer employed, designatedherein as copolymer #5, is a polyoxyethylene adduct of apolyoxypropylene hydrophobic base having a molecular weight of said baseof about 3000 and wherein the oxyethylene content is about 60 percent ofthe total weight of the molecule. The polyoxypropylene hydrophobic baseis prepared by reacting propylene oxide with a propanediol initiator.

EXAMPLE 9

A liquid composition is prepared comprising 36 parts of apolyoxyethylene-polyoxypropylene copolymer, 20 parts ofmethylethylether, 0.1 part of nonoxynol-9, and 43.9 parts of water.

One hundred parts of the above liquid are placed in an aerosolcontainer, the container is pressurized and sealed with a valve and 25parts of a propellant, namely dimethylether, are added through thevalve. The contents are shaken and 1 ml sprayed onto the cervix. A thinfilm forms initially completely coating a cervix after which thedimethylether and ethylmethylether evaporate whereby a foamy gel formson the surface. The composition effectively immobilizes spermatazoa.

The polyoxyethylene-polyoxypropylene copolymer employed, designatedherein as copolymer #6, is a polyoxyethylene adduct of apolyoxypropylene hydrophobic base having a molecular weight of said baseof about 3000 and wherein the oxyethylene content is about 65 percent ofthe total weight of the molecule. The polyoxypropylene hydrophobic baseis prepared by reacting propylene oxide with a propanediol initiator.

EXAMPLE 10

A composition is prepared comprising 15.0 parts of apolyoxyethylene-polyoxypropylene copolymer, 30 parts of glycerine, 0.1part of nonoxynol-9, and 54.9 parts of water. The composition is cooledto 5° C.

One hundred parts of the above liquid are placed in an aerosolcontainer, the container is pressurized and sealed with a valve and 25parts of a propellant, namely dimethylether, are added through the valvewhich dissolves the above composition to form a liquid. The contents areshaken and 1 ml sprayed onto the cervix. A thin film forms initiallycompletely coating a cervix after which the dimethylether andethylmethylether evaporate whereby a foamy gel forms on the surface. Thecomposition effectively immobilizes spermatazoa.

The polyoxyethylene-polyoxypropylene copolymer employed, designatedherein as copolymer #7, is a polyoxyethylene adduct of apolyoxypropylene hydrophobic base having a molecular weight of said baseof about 4000 and wherein the oxyethylene content is about 70 percent ofthe total weight of the molecule. The polyoxypropylene hydrophobic baseis prepared by reacting propylene oxide with a propanediol initiator.

The embodiments of the invention in which an exclusive privilege orproperty is claimed are defined as follows:
 1. A pressurizedcontraceptive composition in an aerosol container capable of forming aspray upon release of pressure therefrom which composition is a liquidinside the container and forms a gel on contact with living tissue andwhich comprises by weight about 20 to 60 percent water, about 20 to 80percent propellant, 0 to about 40 percent of a non-propellant volatilesolvent, about 0.02 to about 1.5 percent of a sperm function inhibitor,and 7.5 to 30 percent polyoxyethylene-polyoxypropylene copolymer of theformula:

    Y[(H.sub.3 H.sub.6 O).sub.n (C.sub.2 H.sub.4 O).sub.m H].sub.x

wherein Y is the residue of a water-soluble organic compound containingtherein x active hydrogen atoms; n is an integer; x is an integergreater than 1; the value of n and x are such that the molecular weightof the oxypropylene groups is from about 3000 to 4500 and the value of mis such that the oxyethylene groups constitute about 50 to 90 percent ofthe total weight of the compound.
 2. The composition of claim 1including about 1.0 to 30 percent of at least one adjuvant.
 3. Thecomposition of claim 1 wherein Y is propylene glycol whereby theresulting compounds have the structure HO(C₂ H₄ O)_(m) (C₃ H₆ O)_(n) (C₂H₄ O)_(m) H wherein n has a value such that the oxypropylene groups havea molecular weight of about 3000 to 4500 and m has a value such that theoxyethylene groups constitute about 50 to 90 percent of the total weightof the compound.
 4. The composition of claim 3 including about 1.0 to 30percent of at least one adjuvant.
 5. The composition of claim 3 whereinthe amount of non-propellant volatile solvent is about 10 to 25 percent.6. The composition of claim 5 including about 5.0 to 10 percent of atleast one adjuvant.
 7. A pressurized contraceptive composition in anaerosol container capable of forming a spray upon release of pressuretherefrom which composition is a liquid inside the container and forms agel on contact with living tissue comprising by weight about 20 to 80percent propellant about 20 to 60 percent water, about 0.02 to 1.5percent sperm function inhibitor and about 7.5 to 30 percentpolyoxyethylene-polyoxypropylene copolymer of the formula:

    HO(C.sub.2 H.sub.4 O).sub.m (C.sub.3 H.sub.6 O).sub.n (C.sub.2 H.sub.4 O).sub.m H

wherein n has a value such that the molecular weight of the oxypropylenegroups is from about 3000 to 4500; and the value of m is such that theoxyethylene groups constitute about 50 to 90 percent of the total weightof the compound and the water:copolymer ratio is not greater than about5.7:1.
 8. The composition of claim 7 including about 10 to 30 percent ofat least one adjuvant.
 9. The composition of claim 7 including about 5.0to 10 percent of at least one adjuvant.
 10. A contraception processcomprising spraying a gel composition in liquid form from an aerosolcontainer onto a cervix, whereby a gel is formed on contact therewith,said composition comprising by weight about 20 to 60 percent water,about 20 to 80 percent propellant, 0 to about 40 percent of anon-propellant volatile solvent, 0 to about 1.5 percent sperm functioninhibitor and about 7.5 to 30 percent of apolyoxyethylene-polyoxypropylene copolymer of the formula:

    Y[(C.sub.3 H.sub.6 O).sub.n (C.sub.2 H.sub.4 O).sub.m H].sub.x

wherein n has a value such that the molecular weight of the oxypropylenegroups is from about 3000 to 4500 and the value of m is such that theoxyethylene groups constitute about 50 to 90 percent of the total weightof the compound.
 11. The contraception process of claim 10 wherein Y ispropylene glycol whereby the polyoxyethylene-polyoxypropylene copolymerhas the structure

    HO(C.sub.2 H.sub.4 O).sub.m (C.sub.3 H.sub.6 O).sub.n (C.sub.2 H.sub.4 O).sub.m H

wherein n has a value such that the oxypropylene groups have a molecularweight of about 3000 to 4500 and m has a value such that the oxyethylenegroups constitute about 50 to 90 percent of the total weight of thecompound.
 12. The process of claim 11 including 1.0 to about 30 percentof at least one adjuvant.
 13. The process of claim 11 wherein the amountof non-propellant volatile solvent is about 10 to 25 percent.
 14. Theprocess of claim 13 including about 5.0 to 10 percent of at least oneadjuvant.
 15. A contraception process comprising spraying a gelcomposition in liquid form from an aerosol container onto a cervixwhereby a gel is formed on contact therewith, said compositioncomprising by weight about 20 to 80 percent propellant, about 20 to 60percent water, 0 to about 1.5 percent sperm function inhibitor and about7.5 to 30 percent polyoxyethylene-polyoxypropylene copolymer of theformula:

    HO(C.sub.2 H.sub.4 O).sub.m (C.sub.3 H.sub.6 O).sub.n (C.sub.2 H.sub.4 O).sub.m H

wherein n has a value such that the molecular weight of the oxypropylenegroups is from about 3000 to 4500; and the value of m is such that theoxyethylene groups constitute about 50 to 90 percent of the total weightof the compound and the water:copolymer ratio is not more than about5.7:1.
 16. The process of claim 15 wherein said composition includesabout 1.0 to 30 percent of at least one adjuvant.